Support for abrasive disks



Nov. l2, 1946. F. DE AMlczHEL SUPPOR-'Jl FOR ABRASIVE DISKS Fiied June so, m45V Patented Nov;-12, '19l4 6 SUPPORT FOR ABRASIVE DSKS Frank De Michel, Chicago, lill., assignor of twenty-iive .per cent to Walter .'i. Jacobsen, twelve and one-half pier cent to Russell IF. Barsotti, and twelve and ond-haii per cent to Vincent li. Barsotti, all of Chicago, Ill.

application .inne 3o, 1945, serial No. 602,502

' 15' claims. (ci. 51-197) This invention relates to supports adapted to carry abrasive disks for surface finishing and the like and more particularly to such supports for use on power operated tools. i

It is a general object of my present invention to provide an improved support for abrasive disks which promotes better wearing qualities and longer life for the supported abrasive disks by providing for the effective cooling of the abrasive disks during use.

Another object of the invention` is to provide an improved support-for abrasive disks comprising a somewhat flexible laminated type 'of abrasive disk backing structure made up of a series of relatively thin backing disks of varying diameters assembled in stepped relationship with the largest disk in position to underlie the abrasive disk and wherein the backing disks have radially and circumferentially spaced openings therein for the passage of cooling air to theback of the abrasive disk.

The invention has for another object the provision of an improved support vfor abrasive disks in which the abrasive disk backing members have passages therein for the ow of coolingair and a spacer is provided normally to separate the abrasive disk from the adjacent backing member when and on the side where no pressure is apcharacters of reference indicate similar parts throughout the several views.

Referring to the single sheet of drawings: Fig. 1 is a top plan view of a support for abrasive disks whjch embodies my invention in a pr ferred form; l

Fig. 2 is a side sectional view of the abrasive disk support shown in Fig. l with the section taken substantially on a line 2-2 of Fig. 1 and showing the mounting of the support relative to a driving spindle;

Fig. 3 is a fragmentary and radial sectional view of a modified form of my invention;

Figs. 4 and 5 are fragmentary stepped sectional views each indicating modiiications of my invention with the sections for each taken substan- 'Y tially as indicated bythe stepped section lines 5 5 in Fig. '1, Fig'. 4 being a view of the modiication shown in Fig. 3;

Fig. 6 is a fragmentary sectional view similar to Fig. 2 but illustrating a modification of my invention; and

Fig. 7 is a fragmentary plan view illustrating a portion of the abrasive disk support structure In the exemplary embodiment of my invention f depicted in Figs. 1 and 2, the support for abraplied in grinding so as to further facilitate the flow of cooling air over the back of the abrasive disk.

As another object, my invention comprehends the provision-of a support for abrasive disks having passages therein for the low of cooling air to the abrasive disk, which passages are angularly disposed in relation to the direction of movement in use to induce the flow of the air.

It is also within'the purview of my invention to provide a support for abrasive disks having air l passages therein for the flow of cooling air to the abrasive disk and adjacent air scoops disposed for inducing the flow of the cooling air during use.

My invention further comprehends the 'use `oi air now passages in a 'supporti for abrasive disks which are .so disposed relative to one another and to the direction of motion in operation that.

a flow of the cooling air results.

Another object of the present invention is to provide a support for abrasive disks incorporat ing one or more of the features outlined thus far and incorporated in an assembly adapted to mounting as a unit.

. Other objects and advantages of the invention will be apparent from the following description andthe accompanying drawing in which similar sive disks includes a hub I0 which is adapted to be mounted in driven relation upon a projecting threaded stud I2 at the end of a driving spindle I3; the hub lll having an axial threaded bore I4 screwed onto the stud. On its forward face the hub I0 has a relatively at surface I5 projecting radially from an integrally formed shoulder I6. The shoulder I6 projects forwardly from the flat surface I5 and is concentric with respect to the axis of the spindle I3 and stud I2. Near the periphery an edge portion Il of the hub is desirably rounded away from the fiat surface I5.

To provide a relatively stiff but flexible backing for the outer portion of-an abrasive disk, a plurality of backing disks I8, I9 and 20 of different radii are disposed in face-tc-facefandstepped relationship. Each of the backing disks has a central opening 22 adapted to iit over the shoulder I6. The abutment of the backing disks against the shoulder I6 notonlyfserves to locate the backing disks concentrically with respect to the hub and spindle, but. also provides reenforcement for the absorption of radial forces.

Although there are various materials of which the backing disks might be made to function in accordance with the principles 'of my invention, I have foundphenol ber disks to be light, durable and satisfactory for providing the desired support and flexibility.

The different radii and stepped relationship of the disks provides greater flexibility of the abrasive disk support near the outer edge of the abrasive disk. Although various numbers and thicknesses of backing disks are feasible for.

V the largest disk provides the backing surface for anabrasive disk 23.

. In accordance with my invention andin order to improve theV operation and prolong the life of the abrasive disk, I'have provided each disk with atleast one series of circumferentially separated air passages 24 for the passage of cooling air to the back surface of the abrasive disk during operation. The air passages through the adjacent super-imposed backing 'disks are aligned in the assembled relationship of the backing disks so thattogether they form series of radially and circumferentially spaced air passages.

In the form of my invention depicted in Figs.- 1 and 2, the air passages extendaxially through ,the backing disks and the flow of cooling vair therethrough is induced by the rotation of the support and its accompanying abrasive disk in use.

Further to improve the flow of cooling air across the back surface of the abrasive disk, a

relatively thin ring-like spacer plate is mounted against the backing face provided by the backing disk 29 near the locating shoulder I6 and inwardly of the rst series of air passages Cil 29 and is gripped and deformed between that nut `and the adjacent surface of the hub I0.

In the modified form of my invention'which is illustrated inthe sectional views of Figs. 3 and 4, the backing disks I8a, YI9a, and 20a are similar to those depicted and4 described with reference to Fig. 2 and may be similarly mounted. However, in these backing disks the ai'r passages 24a are disposed 4angularly with reference tothe direction of rotation of the spindle and abrasive disk soas to induce the flow of air therethrough and across the surface of the abrasive disk.

. Although it is understood, that all of the` air passages might very Well be similarly disposed with reference to the direction of rotation and so that the cooling air would flow inwardly to- Ward4 the abrasive disk through those passages and exhausted at the edges of the abrasive disk, I have illustrated a disposition of passages such that air flows inwardly toward the vabrasive disk through a part of the passages and flows outwardly from the `surface of the abrasive disk1 through others of the passages.

To effect air flow in the direction depicted by the arrows inFig. 4, when the direction of movement of the disk is as indicated, the air passages through which the cooling air ows to the abrasive disk are sloped away from the direction of movement from back to front While .the passage for the ow of air from the abrasive disk is slopedaway from the direction of -movement from'front to back. It may be understood that b theA slope of4 the air passages in each instance 2|. Desirably` the assembled backing disks and spacer lplate are removably secured to the hub I0 by fastening .means such as a series of As indicated in Fig. 2the spacer plate 25 serves normally to space the abrasive disk from the backing face when there isno pressure applied to the surface of the abrasive disk in use or over the area to which there isv no pressure applied in use. 'I'he abrasive disk of course flexes to a position against the backing surface whenA operating pressure is applied to the abrasive disk surface. Although the spacer plate is relatively thin, the normal separation between the abrasive disk and the backing face provides for the circulation of cooling air across practically the entire back surface of the useful area. of the'abrasive disk.r f

With the type of hub disclosed inFig. 2, the portion thereof which is radially inward of the shoulder I6 and adjacent the bore I4 is .cupped axially as at 21 and has a recess 28 at the outer end of the bore Il to accommodatean abrasive` disk holding nut 29 which isthreaded onto the end of the stud I2. Desirably the end surface of the nut 29 does not project beyond the plane 1 of the surface of Vthe abrasive disk and thus does not interfere with the grinding operation.v

For adaptation to the mounting disclosed, the abrasive disks have a central opening 30 which fits over a flange 32 on the nut 29. The inner portion of the abrasive disk underlies the mit is substantially transverse to a tangentl at a radius disposed outwardly from the axis of rotary movement. l

Further to enhance the flow of air in the form disclosed in Figs. 3 and 4, air scoops such as 33, 34 and 35 are disposed adjacent the air passages and on one side thereof in relation to the .direction of motion. In the disclosed form4 the air` scoops are integrally formed on the back surfaces of 'the backing disks. Sinc'e the scoops project from those surfaces and are disposed with reference to the direction of rotation, theyl tend to increase the induced flow of cooling air through the passages.

In'the modified form of my invention disclosed ln Fig. 5, the structure of the backing disks I8b, I9b and 2Ub is similar to the structure of the disks I8a, I9a and 20a of Figs. 3 and 4 except that the air scoops have been omitted. The' angular disposition of thefair passages 2lb is "similar to that depicted and describedv with re- Ithe flange 32 of the nut 29 to .center spect to Figs. 3 and 4.

In Fig. 6 I have depicted a modified type of hub and a -mounting assembly adapted to use therewith. The mounting assembly disclosed is adaptable to connection with a spindle having a relatively fiat front surface. In this instance the spindle is provided'with a flexible flange 36 which is made of a material such as rubber. For mounting thereon, theassembly including the backing disks I8, I9 and-20 and the spacer plate 25, are secured by fastening means such as the screws 26 to a mounting plate 31. At its center themounting plate 31 has a bore 38 which fits the backing structure with reference to the spindle stud I2. As in the previous form, the nut 29 is threaded onto-'the stud I2 and grips the inner portion 1 of the abrasive disk. to -hold it in place.

backing disks of the type disclosed and which advantageously utilize the flow oi cooling air through appropriate air passages, and either with or without the accompanying spacer plate 25, are adaptable to the various types of mounting hubs which are presently in use.

While I have 'illustrated a preferredembodi-4 ent of the United States is:

l. A support for an abrasive disk adapted to be mounted on a spindle and comprising, in combination, a hub having a central spindle receiv-v ing opening and a at face portion extending radially outwardly from a locating shoulder, the portion of said hub inwardly of the shoulder being cuppedL around the spindle receiving opening, a plurality of normally iiat and relatively thin ber disks having diierent radii and placed faceto-face in stepped relationship with the smaller disks adjacent said at face of the hub, said disks having central openings adapted to fit over said shoulder and series 'of radially and circumferentially spaced air passages therein, the air passages of adjacent disks being aligned for the flow of cooling air therethrough, a at and. relatively thin ring-like spacer plate mounted against the face of one of the disks opposite said ilat surface of the hub, means for holding said disks and ring-like plate together and in place against the iiat surface of the hub, and means adapted to engage said spindle and i'lt into the cupped portion of said hub for holding an abrasive disk in place upon the support, and said ring-like spacer plate normally holding the vabrasive disk away from the adjacent fiber o .sk. 1

2. A support for abrasive disks adapted to be mounted on a spindle and comprising, in com bination, a plurality of normally flat backing disks of relatively flexible material having different radii and superimposed in face-to-face and stepped relationship with the larger disk forming a backing face for the abrasive disk, said disks having central mounting openings and series of radially and circumferentially spaced vair passages extending therethrough from face to face, the air passages of adjacent backing disks being aligned for the passage of cooling air therethrough, a iiat and relatively thin ring-like spacer plate mounted against said backing face and adjacent the-central opening therein, and

means for securing said backing disks and spacer plate together in concentric relationship for mounting in driven relationship upon the spindle.

3. In a support for abrasive disks, the combination comprising a plurality of normally flat backing disks of relatively flexible material having diierent radii and superimposed in face-toface and stepped relationship with the larger disk forming a backing face for the abrasive disk, series of radially and oircumferentially spaced air passages extending through said backing disks from face'to face, the air passages of adjacent disks being aligned for the passage of cooling air therethrough, and a relatively thin spacer plate concentrically disposed against said backing face radially inside of said air passages for normally holding tlie abrasive disk in spaced relationship to the backing face.

4. In a support for abrasive disks, the combination comprising a plurality of normally at backing disks of relatively flexible material having diierent radii and superimposed in face-to- 5 face and stepped relationship With the larger disk forming a backing face for the abrasive disk, means for spacing the central portion of the abrasive disk from the backing face, series of radially and circumferentially spaced air passages extending through said backing disks from face to face and the air passages of adjacent disks being aligned for the passage of cooling air therethrough.

5. In a support for abrasive disks adapted to be rotated about a central axis, the combination comprising a plurality of normally flat backing disks of relatively thin fiber material having different radii and superimposed in face-to-face and stepped relationship with the larger disk forming a backing face for the abrasive disk, se-

ries of radially and circumferentially spaced air passages extending axially through the backing disks, and means for holding the air passages of adjacent disks in axial alignment for the passage of cooling air 4therethrough to the abrasive disk.

6. In a support for abrasive disks .adapted to be rotated for use, the combination comprising a plurality of normally ilat backing disks-having diierent -radii and superimposed in face-to-face and stepped relationship with the larger disk forming a backing face for supporting the abrasive disk, said backing disks having series of radially and circumferentially spaced air passages extending therethrough from face to face, the air passages of adjacent disks being aligned for the passage o f cooling air therethrough to l the abrasive disk, and said air passages being angularly disposed in relation to the direction of rotation to induce the ilow of cooling air.

7. In a, support for abrasive disks 'adapted to be rotated for use, the combination comprising a plurality of normally at backing disks having different radii and superimposed in face-to-face and stepped relationship with'the larger disk forming a backing face for supporting theabrasive disk, said backing disks having series f radially and circumferentially spaced air passages extending therethrough from face to face, the air passages oi' adjacent disks being aligned for the passage of cooling air therethrough to the abrasive disk, and said air passages being angularly disposed in relation to the direction of rotation of the abrasive disk to induce the flow of cooling air acrossthe surface thereof, a part of said air passages being angularly disposed to induce the flow of air to the surface of the abrasive disk. and a part of the air passages being angularly disposedv to induce the flow of cooling air away from the abrasive disk.

8.-In a support for abrasive disks adapted to be rotated for use, ,the combination comprising a. plurality of normally flat backing disks having different radii and superimposed in face-to-face and stepped relationship with the larger disk 65 forming a backing face for supporting the abrasive disk, said backing disks having series of radially and circumferentially spaced air passages extending therethrough from face to face, the air p assages of adjacent disks Ibeing aligned for the passage of cooling air therethrough to the abrasive disk, and air scoops projecting from the faces 9. In a support for abrasive disks adapted to be rotated for use, the combination comprising a plurality of normally flat .backing disks having different radii and superimposed in face-to-face and stepped relationship with the larger disk of the backing disks adjacent the air passages and disposed in relation to the direction of rotation to induce the flow of cooling air through the passages and across the surface of the abrasive disk, some of said air scoops being disposed toinduce the fioW of air toward the abrasive disk, and some of said air scoops being disposed to induce the ow of air from the abrasive disk. 10. In a support for abrasive disks adapted to be rotated in use, the combination comprising a backing disk having a normally flat abrasive disk backing portion, said backing disk having therein a series of circumferentially spaced air passages for the flow of cooling air to'the abrasive disk during rotation, and a spacer ring adjacent the backing disk and radially inside said series of air passages for normally spacing the abrasive disk from the backing disk for the ow of air between said disks. 11, In a support for abrasive disks adapted to be rotated in use, the combination comprising a backing disk having a normally at abrasive disk backing portion, said backing disk having therein a series of circumferentially spaced air' passages for the flow of cooling air to the abrasive disk during rotation, and said air passages being angularly disposed in relation to the direction of 8 rotation to inducethe iiow of cooling air across the surface of the abrasive disk.

12. In a support for abrasive disks adapted to be rotated in use, the combination comprising a backing disk having a normally flat abrasive disk backing portion, said backing disk having therein a series of circumferentially spaced air passages for the flow of cooling air to the abrasive disk during rotation, and air scoops on the abrasive disk adjacent said air passages and disposed in relation to the directionof rotation to induce the ow of cooling air to the abrasive disk.

13. In a support for abrasive disks adapted to be rotated in use,.the vcombination comprising a circular backing disk having an abrasive diskbacking surface, and a relatively thin spacer ring adjacent and concentric to the backing surface, said spacer ring being smaller in diameter than the backing disk so as normally to separate and provide space for cooling air between the outer portion of an abrasive disk and the backing surfaces. r

14. In a support for abrasive disks adapted to be rotated in use, the combination comprising a relatively flat backingdisk having an abrasive disk backing surface, and means concentrically disposed on said backing surface and spaced inwardly of the periphery of the backing disk for normally separating the outer portion of an abrasive disk from the backing surface to provide for the passage of cooling air therebetween.

15. In a support for abrasive disks adapted to be rotated in use, the combination comprising a backing disk having an abrasive disk backing surface, and means secured to and covering the centrai portion of the backing surface for normally separating the outer portion of the abrasive disk from the backing surface.

- FRANK DE MICHEL. 

